Question: $g(x) = 2x$ $f(t) = 6t-4(g(t))$ $ f(g(9)) = {?} $
Solution: First, let's solve for the value of the inner function, $g(9)$ . Then we'll know what to plug into the outer function. $g(9) = (2)(9)$ $g(9) = 18$ Now we know that $g(9) = 18$ . Let's solve for $f(g(9))$ , which is $f(18)$ $f(18) = (6)(18)-4(g(18))$ To solve for the value of $f$ , we need to solve for the value of $g(18)$ $g(18) = (2)(18)$ $g(18) = 36$ That means $f(18) = (6)(18)+(-4)(36)$ $f(18) = -36$